Herb Kelleher, who co-founded pioneering low-cost carrier Southwest Airlines Co and built it into an industry powerhouse stamped with his colorful, unconventional personality, died on Thursday at age 87, the U.S. carrier said.

Kelleher set up Southwest with Rollin King more than 50 years ago, with the airline making its first flight in June 1971. King died in 2014, aged 83.

Dallas-based Southwest is known for its quirky culture, closely connected with Kelleher’s maverick image, as well as its fast growth from a regional carrier into one of the biggest in the United States.

The airline flew short flights known as point-to-point, rather than the hub-and-spoke model of its bigger rivals, and used a single model of aircraft, Boeing Co’s 737, to cut complexity and cost.

Southwest “rewrote airliner service in the U.S. (and) became the forerunner of many, many low cost carriers across the globe,” aviation analyst Scott Hamilton said in aerospace publication Leeham News.

Southwest’s cabin crews have become known for their good humor – a legacy of Kelleher, memorialized in a “laugh button” that visitors could press inside the company’s headquarters to hear his famous cackle.

Kelleher won the affection of customers and employees with low fares, good wages and his own high spirits. He sought to instill a sense of fun among employees, sometimes showing up in costume or helping unload baggage.

“A company is stronger if it is bound by love rather than by fear,” he was once quoted as saying.

Kelleher was also known for his fondness for smoking and bourbon.

John Plueger, chief executive of Air Lease Corp, said on Thursday that when he first met Kelleher more than 30 years ago, Kelleher was about to deliver a speech at a New York hotel. “The manager asked that he refrain from smoking. Herb looked up, smiled, and said: ‘No smokey, No talkey.’”

Kelleher was a formidable industry competitor as well.

“There aren’t a whole lot of individuals who you can point to that single-handedly contributed to building a demonstrable portion of the modern economy. Herb Kelleher was one,” tweeted Jon Ostrower, an independent aviation commentator and editor of TheAirCurrent.com.

“His model spawned the global democratization of the affordable movement of humanity by air.”

‘I LIKE TO WIN’

The New Jersey-born Kelleher served as Southwest’s executive chairman for 30 years until 2008 and was chief executive from September 1981 to June 2001.

Kelleher was long a towering figure in the U.S. airline industry along with Bob Crandall, his rival at American Airlines and polar opposite in style. The two built different business models and competed fiercely but with mutual respect.

“It was very hot competition and I like to win,” Kelleher told NPR in a 2016 podcast. Crandall, captured in a YouTube video, once serenaded Kelleher with a version of “My Way,” the song popularized by Frank Sinatra.

Steven Udvar-Hazy, executive chairman of Air Lease and a pioneer of the aircraft leasing industry, whose expansion coincided with the rise of budget carriers, paid tribute to Kelleher as “the builder of the world’s most successful low fare airline.””Herb: a final Wild Turkey Bourbon toast from all of your closest friends,” he added.